A voltage doubler is used to increase the voltage level in a circuit beyond what is available from a given input voltage. A differential implementation of a voltage doubler generates a differential output voltage that is double the value of a differential input voltage. In certain implementations, when a differential output voltage is passively generated, the common-mode level of the differential output voltage is not well-defined.
It would be desirable to provide a passive differential voltage doubler that has the advantages of providing a well-defined common-mode output voltage as well as being simple to design.